Cationic electrodeposition coating has been used for undercoating bodies and parts of automobiles, and required to form coating films with high corrosion resistance. However, lead compounds, which have been used as highly corrosion-resistant rust preventive pigments, are not preferred from an environmental point of view. Consequently, various non- or less-toxic, lead-free, rust preventive pigments have been developed and described in JP-A-2000-309730, etc. Proposed in JP-A-2000-309730 is a cationic electrodeposition coating composition containing a basic zinc silicate having a zinc/silicon mole ratio of 1.1/1 to 2.5/1 as the rust preventive pigment.